Development.IDE.GHC.Util

General utility functions, mostly focused around GHC operations.

Documentation

modifyDynFlags :: GhcMonad m => (DynFlags -> DynFlags) -> m ()

Used to modify dyn flags in preference to calling setSessionDynFlags, since that function also reloads packages (which is very slow).

evalGhcEnv :: HscEnv -> Ghc b -> IO b

Run a Ghc monad value using an existing HscEnv. Sets up and tears down all the required pieces, but designed to be more efficient than a standard runGhc.

GHC wrappers

printRdrName :: RdrName -> String

Pretty print a RdrName wrapping operators in parens

printName :: Name -> String

Pretty print a Name wrapping operators in parens

data ParseResult a

The result of running a parser.

Constructors

POk

The parser has consumed a (possibly empty) prefix of the input and produced a result. Use getMessages to check for accumulated warnings and non-fatal errors.

Fields

• PState

  The resulting parsing state. Can be used to resume parsing.

• a

  The resulting value.

PFailed

The parser has consumed a (possibly empty) prefix of the input and failed.

Fields

• PState

  The parsing state right before failure, including the fatal parse error. getMessages and getErrorMessages must return a non-empty bag of errors.

runParser :: DynFlags -> String -> P a -> ParseResult a

lookupPackageConfig :: Unit -> HscEnv -> Maybe UnitInfo

Given a Unit try and find the associated PackageConfig in the environment.

textToStringBuffer :: Text -> StringBuffer

Convert from the text package to the GHC StringBuffer. Currently implemented somewhat inefficiently (if it ever comes up in a profile).

bytestringToStringBuffer :: ByteString -> StringBuffer

stringBufferToByteString :: StringBuffer -> ByteString

moduleImportPath :: NormalizedFilePath -> ModuleName -> Maybe FilePath

Given a module location, and its parse tree, figure out what is the include directory implied by it. For example, given the file /usr/Test/Foo/Bar.hs with the module name Foo.Bar the directory /usr/Test should be on the include path to find sibling modules.

cgGutsToCoreModule :: SafeHaskellMode -> CgGuts -> ModDetails -> CoreModule

Convert from a CgGuts to a CoreModule.

fingerprintToBS :: Fingerprint -> ByteString

Convert a Fingerprint to a ByteString by copying the byte across. Will produce an 8 byte unreadable ByteString.

fingerprintFromByteString :: ByteString -> IO Fingerprint

fingerprintFromStringBuffer :: StringBuffer -> IO Fingerprint

Take the Fingerprint of a StringBuffer.

fingerprintFromPut :: Put -> IO Fingerprint

General utilities

readFileUtf8 :: FilePath -> IO Text

Read a UTF8 file, with lenient decoding, so it will never raise a decoding error.

hDuplicateTo' :: Handle -> Handle -> IO ()

A slightly modified version of hDuplicateTo from GHC. Importantly, it avoids the bug listed in https://gitlab.haskell.org/ghc/ghc/merge_requests/2318.

setHieDir :: FilePath -> DynFlags -> DynFlags

dontWriteHieFiles :: DynFlags -> DynFlags

disableWarningsAsErrors :: DynFlags -> DynFlags

printOutputable :: Outputable a => a -> Text

Print a GHC value in defaultUserStyle without unique symbols. It uses showSDocUnsafe with unsafeGlobalDynFlags internally.

This is the most common print utility. It will do something additionally compared to what the Outputable instance does.

1. print with a user-friendly style: a_a4ME as a.
2. unescape escape sequences of printable unicode characters within a pair of double quotes

getExtensions :: ParsedModule -> [Extension]